The following tables categorize the fair values of cash, cash equivalents, short-term investments and long-term investments measured at fair value on a recurring basis on our balance sheets (in thousands):


	March 31, 2024		December 31, 2023
Cash and cash equivalents:
Cash	$	1,594	$	1,521
Money market funds		5,315		4,285
Government and agency notes		14,904		14,946
Total cash and cash equivalents	$	21,813	$	20,752

Short-term investments:
Certificates of deposit	$	490	$	729
Government and agency notes		45,520		53,578
Total short-term investments	$	46,010	$	54,307

The Company's investments are classified as available-for-sale securities. As of March 31, 2024, the weighted average remaining contractual maturities of available-for-sale securities was approximately 2 months. The unrealized gain (loss) activity related to the Company’s available-for-sale securities is included in the Company’s accumulated other comprehensive income. There were no significant realized gains or losses recognized on the sale or maturity of available-for-sale securities for the three months ended March 31, 2024 and 2023, and as a result, the Company did not reclassify any amounts out of accumulated other comprehensive income. Based on the Company’s review of its available-for-sale securities, the Company has a limited number of available-for-sale securities in insignificant loss positions as of March 31, 2024. No other-than-temporary impairments on these securities were recognized for the three months ended March 31, 2024 and 2023.

The Company periodically assess our investment in available-for-sale securities for impairment losses and credit losses. The amount of credit losses are determined by comparing the difference between the present value of future cash flows expected to be collected on these securities and the amortized cost. Factors considered in assessing credit losses include the position in the capital structure, vintage and amount of collateral, delinquency rates, current credit support, and geographic concentration. There have been no impairment and credit losses related to available-for-sale securities for the three months ended March 31, 2024 and 2023.

For available-for-sale debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value and recognized in interest and other income, net in the statement of operations and comprehensive loss. If neither criteria is met, the Company evaluates whether the decline in fair value is related to credit-related factors or other factors. In making this assessment, management considers the extent to which fair

value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. Credit-related impairment losses, limited by the amount that the fair value is less than the amortized cost basis, are recorded through an allowance for credit losses in interest and other income, net.

Any unrealized losses from declines in fair value below the amortized cost basis as a result of non-credit factors are recognized in accumulated other comprehensive income, net of tax as a separate component of stockholders’ equity, along with unrealized gains. Realized gains and losses and declines in fair value, if any, on available-for-sale securities are included in interest and other income, net in the condensed statement of operations and comprehensive loss.

For purposes of identifying and measuring credit-related impairments, the Company’s policy is to exclude applicable accrued interest from both the fair value and amortized cost basis of the related security. The Company has elected to write-off uncollectible accrued interest receivable balances in a timely manner, which is defined by the Company as when interest due becomes 90 days delinquent. The accrued interest write-off will be recorded by reversing interest income. Accrued interest receivable is recorded in other current assets on the condensed balance sheets.

The following table summarizes the available-for-sale securities (in thousands):


	Fair Value Measurements as of March 31, 2024
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Money market funds	$	5,315	$	—	$	—		$	5,315
Certificates of Deposit		490		—		—			490
Government and agency notes		60,426		1		(3	)		60,424
Total cash equivalents and investments	$	66,231	$	1	$	(3	)	$	66,229

Classified as:
Cash equivalents (original maturities within 90 days)								$	20,219
Short-term investments (maturities within one year)									46,010
Total cash equivalents and investments								$	66,229


	Fair Value Measurements as of December 31, 2023
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Money market funds	$	4,285	$	—	$	—		$	4,285
Certificates of Deposit		735		—		(6	)		729
Government and agency notes		68,528		13		(17	)		68,524
Total cash equivalents and investments	$	73,548	$	13	$	(23	)	$	73,538

Classified as:
Cash equivalents (original maturities within 90 days)								$	19,231
Short-term investments (maturities within one year)									54,307
Total								$	73,538